Men and women at the intelligence agency keep us safe and don't threaten our privacy.

For six decades, the National Security Agency has been making codes and breaking codes to give the United States and its allies an edge against foreign adversaries. Hundreds of thousands have served this nation faithfully; 173 of them gave their lives in the line of duty. Such efforts have allowed the nation to defeat threats from those who never tire of trying to harm our people, partners, and way of life.

This work itself is now under assault.

A year later, we still don't know the full impact of the disclosures that stemmed from Edward Snowden's theft of classified documents from the NSA. We do know that he has caused more damage to national security than any leaker in U.S. history.

Over the past year, we've watched as terrorists and our adversaries learned from the information Snowden provided, and changed their M.O. His disclosures tipped our hand. As a result, it's unlikely that we'll be able to maintain the successes of the past 13 years in detecting and stopping terrorist attacks and in anticipating and mitigating threats from other quarters such as the proliferation of weapons of mass destruction, various actors and nation states bent on creating regional instability, and the rapid growth in the character, scope and scale of cyber threats. We believe this will be measured in the loss of lives and an increased risk to property, security and safety in the U.S. and around the world.

This is more than a notion.

The University of Maryland's START program tracks terrorist events for the State Department. From their count, in 2012 there were 6,771 terrorist attacks worldwide resulting in more than 11,000 deaths. According to the State Department, almost 18,000 people died in 2013 as a result of terrorist attacks. Yet the relative safety in the U.S. and Europe is taken for granted. In reality, it is attributable to the hard work of security institutions at local, state, and federal levels – all collaborating to detect threats before they turn deadly.

What of the original claims made by Snowden and his supporters that their actions were justified as a means to reveal a gross imbalance between security and privacy? Those claims have far too often been misrepresented or skewed to tell only a small part of the larger story.

The reality in the fuller telling of this tale is that the men and women who strive to defend the nation at institutions like NSA do not cherry-pick the parts of the Constitution they will follow. Their work is grounded in an adherence to each and every one of its provisions. The agency is charged with delivering national security, but not at any price.

It's been said that the debate over U.S. surveillance programs centers on a "choice" between security and privacy. Or, that security and privacy are like "scales of justice": When one gains, the other loses.

We believe security and privacy are like rails under a train, where each must be established on a firm foundation and the sum of the two working together allows the engine to proceed with confidence.

NSA's authorities and processes are complex. But the issues are not complicated:

NSA adheres to the requirements set out in the Fourth Amendment and respects the privacy of U.S. persons.

NSA does not hide information from its overseers. The agency welcomes external oversight and accountability as the necessary price of the authorities delegated to NSA.

NSA employs a broad range of directed and self-imposed controls to limit its activities to those explicitly authorized. And it regularly reports to its oversight bodies, which operate across all three branches of government.

NSA does not set its own agenda. Everything that it does is in response to specific, vetted foreign intelligence requirements. Moreover, NSA does not collect everything. There must be a valid foreign intelligence purpose. Period.

NSA has played strictly by the rules, supporting both the spirit and the letter of the law. As President Obama said in his January 17 speech to the nation: "The men and women of the Intelligence Community, including NSA, consistently follow protocols designed to protect the privacy of ordinary people. They are not abusing authorities in order to listen to your private phone calls or read your e-mails." Last year, an Independent Review Group appointed by the president also determined that NSA followed the rules that were established by all three branches of government.

This is not to say the programs are perfect. Modifications have been made over the years and will continue to be made in the future as a result of this public debate. For example, the full-time Civil Liberties and Privacy Officer at NSA, put in place by President Obama, will help produce greater trust between the American people and NSA.

Liberty and security are not competing interests. We have always believed the two are co-dependent. We can't have liberty without security. Security without liberty is of little value. We need to constantly ensure that our government is vigilant about protecting each of them.

Let's continue this debate. It's good for the nation. After all, dialogue and dissent are a part of what makes our country great. But let's do so with the facts in hand. National security is too important to be reduced to nothing more than a war of sound bites.

Gen. Keith B. Alexander is the former director of the National Security Agency. John "Chris" Inglis is the former deputy director.